Identified losses from fraud involving credit cards issued in Japan following the theft of card data in the United States have reached 37 million yen, industry sources said Tuesday.

The losses include 10 million yen found at UFJ Card Co., 6.5 million yen at Aeon Credit Service Co., 5.91 million yen at Toyota Finance Corp. and 2.89 million yen at Mitsui Sumitomo Card Co., they said.

Data on some 39,000 Visa-linked credit cards issued in Japan might have been stolen from CardSystems Solutions Inc., a card data-processing firm in the United States, Visa International Inc. said, recommending that affected cardholders replace their credit cards.

In addition, data on 21,000 MasterCard-linked Japanese cards might have been leaked from the U.S. firm, the Ministry of Economy, Trade and Industry said.

JCB Co. said 31 JCB cards are among the credit cards whose data might have been stolen from CardSystems Solutions.

Some Japanese credit card companies said data stolen from the U.S. firm might have been used for fraudulent purposes in Japan, including unauthorized purchase of DVD players.

Identified losses in Japan are likely to increase down the track as some card firms are still investigating the magnitude of possible losses, industry sources said.

Reports said losses involving the U.S. card data theft have been found in other Asia-Pacific economies including Singapore, Australia, Hong Kong and New Zealand. Data on some 20,000 Singaporean cardholders were reportedly been stolen from the U.S. firm.

At a press conference Tuesday, Economy, Trade and Industry Minister Shoichi Nakagawa urged Japanese credit card companies to tighten their computer system security to prevent further leakage of personal information following the security breach that surfaced last week in the United States.

''We cannot be defeated in the battle against those attempting to breach computer security. We will ask Japanese data-processing companies to check their systems,'' Nakagawa said.

In Japan, about 260 million credit cards had been issued as of the end of fiscal 2003 through March 31, 2004. Industry sources estimate half of those cards were issued in alliance with MasterCard or Visa.

Source: Agencies